package com.gowants.pems.util;

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;

import javax.servlet.http.HttpServletRequest;

/**
 * 常用获取客户端信息的工具
 * 
 */
public final class NetworkUtil {
    /**
     * Logger for this class
     */
//    private static Logger logger = Logger.getLogger(RandomCodeUtils.class);

    /**
     * 获取请求主机IP地址,如果通过代理进来，则透过防火墙获取真实IP地址;
     * 
     * @param request
     * @return
     * @throws IOException
     */
    public  static String getIpAddress(HttpServletRequest request) throws IOException {
        // 获取请求主机IP地址,如果通过代理进来，则透过防火墙获取真实IP地址
    	String ip = null;
    	//X-Forwarded-For：Squid 服务代理
        String ipAddresses = request.getHeader("X-Forwarded-For");

        if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //Proxy-Client-IP：apache 服务代理
            ipAddresses = request.getHeader("Proxy-Client-IP");
        }

        if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //WL-Proxy-Client-IP：weblogic 服务代理
            ipAddresses = request.getHeader("WL-Proxy-Client-IP");
        }

        if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //HTTP_CLIENT_IP：有些代理服务器
            ipAddresses = request.getHeader("HTTP_CLIENT_IP");
        }

        if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //X-Real-IP：nginx服务代理
            ipAddresses = request.getHeader("X-Real-IP");
        }

        //有些网络通过多层代理，那么获取到的ip就会有多个，一般都是通过逗号（,）分割开来，并且第一个ip为客户端的真实IP
        if (ipAddresses != null && ipAddresses.length() != 0) {
            ip = ipAddresses.split(",")[0];
        }

        //还是不能获取到，最后再通过request.getRemoteAddr();获取
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            ip = request.getRemoteAddr();
        }
        // 解决请求和响应的IP一致且通过浏览器请求时，request.getRemoteAddr()为"0:0:0:0:0:0:0:1"
        if("0:0:0:0:0:0:0:1".equals(ip)){
        	ip = getHostAddress();
        }

        return ip;
    }
    
    private static String getHostAddress(){
        // 根据网卡取本机配置的IP
        InetAddress inet = null;
        try {
            inet = InetAddress.getLocalHost();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
        return inet.getHostAddress();
    }

}
